InGaAs Quantum Dot Growth on InAs(111) and GaSb(111) with Molecular Beam Epitaxy

In this study we have mapped the growth parameters for optimal homoepitaxy of InAs on InAs(111)A substrates using molecular beam epitaxy. Increasing the substrate temperature reveals a transition from 2D flat island growth to step-flow. The optimized parameters we established (substrate temperature = 500° C, growth rate = 0.12ML/s and V/III ratio = 48) produce an atomically flat surface, free of 3D imperfections. We study material quality using photoluminescence and have established a relationship between InAs(111)A surface smoothness and optical quality. This work paves the way for integrating the 6.1 Å family of semiconductors with the desirable properties of the (111) crystallographic orientation. In addition, we will present preliminary results demonstrating the self-assembly of InGaAs quantum dots on these smooth InAs(111) and GaSb(111) surfaces, indicating new paths towards ultra-low bandgap tunable light emitters for infrared optoelectronics.